Automatic wired->wireless network failover?

[orev]

I'm on my home network, using a typical Linksys router. When I'm at my desk I plug in the network cable, so I get better speeds. When I'm away from the desk, I use the wireless. What I would really like (and I think the macs do this), is to be able to unplug the network cable and have the system automatically switch over to using wireless, keeping all the connections alive (staying on the same IP address).

I'm sure it could be done by doing some IP address/MAC address magic, and I'm wondering if anyone knows how to do it, or if there's a way to set this up?

Thanks

Using Vista Ultimate 64bit